Intermittent feed for motion picture apparatus



0a. 15, 1935. J, BRIGGS 1 2,017,111 '1 1 INTERMITTBNT FEED FOR MOTION PICTURE APPARATUS Filed Dec. 12, 1932 INVENTOR JOSEPH/1. BR/G615 1 ATTORNEY Patented a. 15, 1935 2,017,117 I INTERMITTENT FEED FOR MOTION PICTURE APPARATUS Joseph A. Briggs, Erlton, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application December 12,1932, Serial No. 646,782 2 Claims. (01. 8818.4)

This invention relates to intermittent feeds for motion picture apparatus and more particularly the variety thereof which is adapted to intermittently grip the film and move it forward by the reciprocatory action of the gripping member.

' The device of my invention includes anarm pivoted at one end and reciprocated by a cam and a connecting rod at its middle portion, while the other end of the rod carries a film-gripping device which 18 so constructed as to grasp the film from both sides simultaneously.

One object of the invention is to provide such a device having extremely light moving parts.

Another object of the invention is to provide a film gripping device which tends to hold the film in its proper path rather than to force it away from such path.

Another object of the invention is to provide an intermittent feed of the intermittent grip type which requires no additional stationary cooperatifilnlgn members at the point of cooperation with the Another object of the invention is a provide a relatively inexpensive and simple device of this type.

The invention will be better understood from the following description when considered in conneetion with the accompanying drawing, and its scope will be pointed out in the appended claims. In the drawing:

- Fig. l is a'front view of the intermittent feed mechanism constructed in accordance with my Brendon and shown as applied to 16 mm. sound Fig. 2 is a horizontal section of the arm, etc. shown in Fig. l and taken along the axis of the arm. I

Fig. 3 is a vertical section through the cam connecting rod and arm of Fig. 1.

Fig. 4 is a vertical section through the film along the line of sprocket holes and showing the gripping mechanism in cooperative relation to a sprocket hole.

Fig. 5 is a view corresponding to Fig. 4 and showing the gripping mechanism at an-intermediate position in its return path.

Referring now to Figure 1, I represents the reciprocating arm of my device which is pivoted upon an appropriate pin or other member 2,

shown morein detail in Fig. 2. This arm is reciprocated vertically by the action of the connecting rod 3 which is attached to the arm bythe pivot member 4 and which is reciprocated yertically by the eccentric 5. This eccentric is, as

shown more in detail in 2nd 3, mounted upon the squared end 6 on the shaft 1, which shaft is driven at an appropriate speed in any usual manner. It will be apparent that rotation of the shaft 1 at a uniform speed will cause-vertical reciprocation. of the arml.

The eccentric 5 and connecting rod 3 are preferably positioned in an aperture 8 in the middle of the arm I in order to save space and at the same time permit a light and strong construction of the arm I. 10

The film gripping device comprises the outer end of the arm I, and a spring actuated member 9 which is secured thereto by appropriate rivets or equivalent I 0 and slightly spaced therefrom by an appropriate spacing member II. This member 9 is provided with a tooth or teeth I2 adapted to cooperate with the sprocket holes in the film, and the elasticity of the member 9 urges the portion I2 thereof toward the end of the arm I.

The member I is sopositioned that the face 20 thereof adapted to cooperate with the spring 9 properly defines the position of; the corresponding face of the fihn at the point where the intermittent is intended to cooperate with and, as shown in Fig. 4, even when the tooth I2 is in a 25 sprocket hole of the film, the spring 9 urges the film against the member I, thereby definitely maintaining it in proper position.

It will be apparent from Fig. 4 that when the arm I is moved downwardly, the tooth I2 will be 30 in a sprocket hole and will carry the film downwardly also. When, however, the arm I has reached the lower limit of its travel and starts on its return path, the tooth I2 will, due to its shape and due to the maintaining of the film in the roller 35 position by the action of pressure of the film gate or tension of the sprockets, or both, be withdrawn from the sprocket hole with which it was in cooperative relation and will slide over the film until it reaches the next sprocket hole in the direction 40 of its travel. During this backward passage of the members I and 9, the member 9 will of course maintain the film in contact with the member I. The stroke of the eccentric 5 and the position of attachment of the connecting rod 3 to the arm' 45 I are so'chosen that the movement of the arm corresponds with the distance which the film is to be moved, and after the eccentric has passed its center position, the arm and the tooth I2 again proceed to pull the film downwardly as shown 50 in Fig. 4.

It will be apparent that, due to the fact that the member 9 is attached to the member I and presses the film thereagainst, there will be no unbalanced lateral pressure upon either the film or 55 thearm I. andthearm l canthereforebe made oi! extremely light material with just sufflcient mechanical strength to withstand the strains in the direction of movement of the film, while any additional support for the film at the point of feeding can be omitted. if so desired.

ping means mounted upon the said am and cooperating with the other face 0! the said film with a uniform pressure at all times.

2. Intermittent feed mechanism for motion picture apparatus comprising an oscillatable arm having an aperture therein. crank means for oscillating said arm located within the said aperture,

a connecting rod connecting the said crank means and the said arm, and a yieldable film engaging ratchet, mounted on the said oscillatable arm.

' JOSEPH A. BRIGGS. 

